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1
Ho, Wai. "GaAs MESFET modeling and its applications." Ohio : Ohio University, 1993. http://www.ohiolink.edu/etd/view.cgi?ohiou1175707072.
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Abbott, Derek. "GaAs MESFET Photodetectors for imaging arrays /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09pha1312.pdf.
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Weissfloch, Phillip. "Iron-GaAs schottky contact for mesfet applications." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61798.
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Elgaid, Khaled Ibrahim. "A Ka-Band GaAs MESFET monolithic downconverter." Thesis, University of Glasgow, 1998. http://theses.gla.ac.uk/1730/.
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The objective of the work of this thesis is to design, fabricate, and characterise a GaAs MESFET based monolithic microwave integrated circuit (MMIC) downconverter which operates at Ka-band frequency (35GHz). In the course of the project active and passive elements required for the MMIC were designed, fabricated, characterised and their equivalent circuit models extracted. Fabrication processes for passives, actives and MMIC were realised using mainly electron beam lithography (EBL) techniques. The main findings of this thesis were: Devices - Influence of gate recess offset on MESFETs The MESFETs were patterned by EBL and gate recessing was accomplished by selective dry etching. The influence of the gate recess offset on the small signal AC equivalent circuit, DC device characteristics, overall high frequency device performance, and low frequency noise behaviour of 0.2 m gate length GaAs MESFETs implemented in the low noise amplifier (LNA) circuit design in this thesis was investigated. Numerical simulations of the AC small signal equivalent circuit dependence were carried out in order to help understand the effects observed. Good qualitative agreement between measured and simulated response was obtained. - Schottky diodes The performance of Schottky-contact diodes used in the MMIC mixer were studied as a function of their geometry and processing conditions. Passives - CPW losses Losses in coplanar interconnect topologies (coplanar waveguide and slotline) using different metallisation processes were investigated. - CPW to slotline transitions A range of coplanar waveguide to slotline transitions required for the MMIC mixer were studied. Broadband performance with insertion loss of < 0.5dB per transition was observed. Transmission line models of the structures have been implemented to enable circuit performance to be predicted and designed to suit the application frequency. The effect of parasitic modes on transitions performance was also investigated.
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Franklin, Andrew John. "Electrical overstress failure in GaAs MESFET structures." Thesis, Loughborough University, 1990. https://dspace.lboro.ac.uk/2134/11006.
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An experimental and theoretical analysis has been carried out into the effects of electrostatic discharge and constant power electrical overstress in GaAs MES structures. An experimental system has been set up to measure the electrical and physical characteristics of such devices when subject to electrical overstress. This system includes computer controlled equipment to analyse the electrical failure waveforms. The results from the experimental study have been analysed to establish any patterns which characterise ESD breakdown. Using a new thermal breakdown model, analytical predictions of the power required to degrade these devices, for both constant power, and electrostatic discharge breakdown, have been carried out.
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Radice, Richard A. "Single-event analysis of LT GaAs MESFET integrated circuits." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA336778.
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Choo, Boy Lee. "Microwave GaAs MESFET circuit design using time-domain simulation." Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356890.
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Davies, Antony. "Characterisation and parameter extraction techniques for GaAs MESFET devices." Thesis, University of Kent, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241552.
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Chun, Carl S. P. (Shun Ping). "Investigation of GaAs MESFET amplifier topologies for optoelectronic receiver applications." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/14813.
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Chueiri, Ivan Jorge. "Uma contribuição ao projeto de CI's com MESFET em GaAs." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261441.
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Orientador : Jacobus Wilibrordus SwartDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Este trabalho visa criar um elo entre processos e projetos de Circuitos Integrados e Dispositivos no Laboratório de Pesquisa e Dispositivos. Na área referente a processos, o Laboratório de Pesquisa e Dispositivos vem desenvolvendo a técnica de "Difusão de Enxofre em Arseneto de Gálio por Processamento Térmico Rápido" e obtendo dispositivos básicos. Dessa forma a partir deste trabalho foram extraidos os parâmetros Spice dos dispositivos em Arseneto de Gálio que vem sendo processados tanto desenvolvemos no Laboratório 39 do LPD. Para um programa de extração (Statz de parâmetros para o modelo de Raytheon et aI.) , utilizado em SPICE3D2 (UCBerkeley). Obtivemos ajustes das curvas caracteristicas experimentais e de modelo com erro menor que 4%. Juntamente com estes parâmetros foram escritos arquivos de tecnologia, que são regras de projetos para o desenho de novos circuitos. Foi desenvolvido um "chipteste" contendo dispositivos e circuitos, com finalidade de se extrair parâmetros e testar a performance de cada um dos circuitos
Abstract: The intent of the thesis. "A Contribution to Integrated Circuit Projects With GaAs MESFET", is to obtain a relationship between the Research on Devices laboratory (lPD) GaAs process and the integrated circuits develop using this process. The LPD develops integrated circuits using the "Rapid Thermal Diffusion of Sulphur in GaAs". The SPICE parameters of the GaAs devices (depletion transistors), made using this process, was extracted. A computer program was developed, that takes as input the carachteristics' curves of a device and gives as output the SPICE parameters according to the Raytheon Model (Statz et aI.). This model is used in the SPICE3-D2 (and upgraded version) developed by UC-Berkeley. We have obtained the experimental characteristics' curves fit with that of the medel with an errer les5 than 4%. We have, also written the technology file/design rules for MAGIC-6.3, for the LPD diffusion process. Using MAGIC we have developed a test chip ("chipteste") with devices and circuits. These devices will be used to extract parameters that will contribute to the fine tuning of the model and the LPD process
Mestrado
Mestre em Engenharia Elétrica
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Griffiths, Timothy Giles d'Arcy. "Magneto-transport properties of GaAs microstructures near the metal-insular transition." Thesis, University of Exeter, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388627.
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Baree, Atiqui Haque. "Analysis and design of GaAs monolithic microwave and mm-wave mixers." Thesis, King's College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267802.
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Webster, Danny Richard. "Developing low distortion linear and nonlinear circuits with GaAs FETs using the Parker Skellern model." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243599.
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Olbers, Robert L. "A physical-based nonlinear model for the GaAs MESFET with parameter optimization." Ohio : Ohio University, 1991. http://www.ohiolink.edu/etd/view.cgi?ohiou1183735375.
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Chu, Eric. "Characterisation & optimisation of computational functional blocks for ATM switches GaAs MESFET technology /." Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09ENS/09ensc559.pdf.
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Kako, Maria Margaret. "Amplificador faixa larga com mesfet de GaAS para sistemas de até 1,5 Gbit/s." Instituto Tecnológico de Aeronáutica, 1989. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=1871.
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Neste trabalho foi implementado um amplificadorpara pequenos sinais e ambiente de 50 com largaura de faixa de 500 KHz a 1,5 GHz (11,5 oitavas) , baseando se em técnicas de circuitos discretos. Utilizando 2 MESFET';s de GaAs, redes de polarizaçãoindutivas e reais de casamento sem perdas o amplificador construído apresentou um gano médio se 27,5 dB com `ripple';de 1,5 dB e uma figura de ruídomenor que 2 dB para freqüência acima de 500 MHz e menor que 3 dBpara freqüências acima de 50 MHz.
Os resultados experimentais obtidos demonstram a validade de procedimento utilizado para o projeto sendo conseguido um excelente desempenho em termos de ganho, largura de faixa e figura de ruído.
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Ward, Allan III. "Residual Stress Effects on Power Slump and Wafer Breakage in GaAs MESFETs." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/30503.
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The objectives of this investigation are to develop a precise, non-destructive single crystal stress measurement technique, develop a model to explain the phenomenon known as 3power slump2, and investigate the role of device processing on wafer breakage. All three objectives were successfully met. The single crystal stress technique uses a least squares analysis of X-ray diffraction data to calculate the full stress tensor. In this way, precise non-destructive stress measurements can be made with known error bars. Rocking curve analysis, stress gradient corrections, and a data reliability technique were implemented to ensure that the stress data are correct. A theory was developed to explain 3power slump2, which is a rapid decrease in the amplifying properties of microwave amplifier circuits during operation. The model explains that for the particular geometry and bias configuration of the devices studied in this research, power slump is linearly related to shear stress at values of less than 90 MPa. The microscopic explanation of power slump is that radiation enhanced dislocation glide increases the kink concentration, thereby increasing the generation center concentration in the active region of the device. These generation centers increase the total gate current, leading to a decrease in the amplifying properties of the device. Passivation layer processing has been shown to both reduce the fracture strength and increase the residual stress in GaAs wafers, making them more susceptible to wafer breakage. Bare wafers are found to have higher fracture strength than passivated wafers. Bare wafers are also found to contain less residual stress than SiON passivated wafers, which, in turn, are found to have less stress than SiN passivated wafers. Topographic imaging suggests that SiN passivated wafers have larger flaws than SiON passivated wafers, and that the distribution of flaw size among SiN passivated wafers is wider than the distribution of flaws in SiON passivated wafers. These flaws are believed to lead to breakage of the device during processing, resulting in low fabrication yield. Both the power slump model and the wafer breakage data show that these phenomena are dependent on residual stress developed in the substrate during device fabrication. Reduction of process-induced residual stress should therefore simultaneously decrease wafer breakage rates and reduce power slump during device fabrication and operation.Ph. D.
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Godts, Pascale. "Modélisation et optimisation en vue de réalisations technologiques de Mesfet et de Tegfet AlGaAs/GaAs." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37613965c.
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Lott, Urs Martin J. "Ersatzschaltung eines GaAs MESFET gewonnen aus Messungen von Betrag und Phase der in ihm erzeugten Harmonischen /." [S.l.] : [s.n.], 1990. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=9279.
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Nuytkens, Peter R. (Peter Read). "A 12-bit 500 MHz GaAs MESFET digital-to-analog converter with p+ ohmic contact isolation." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/12760.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1992.Vita.
Includes bibliographical references (leaves 134-135).
by Peter R. Nuytkens.
M.S.
21
Moughabghab, Raëd. "Conception de filtres continus GaAs haute précision, faible consommation en vue de leur application dans un système de communication mobile." Lille 1, 1997. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1997/50376-1997-63.pdf.
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Les systèmes de communication mobile radiofréquence (rf) utilisent actuellement, pour leur besoin en filtrage, des filtres à ondes de surface, places à l'extérieur des circuits intégrés. Ces filtres non intégrés entrainent des pertes d'insertion, occasionnées par l'interconnexion entre le filtre externe et le circuit intégré, et un encombrement conséquent lie au boitier encapsulant le filtre. Ces inconvénients ont conduit à la recherche de méthodes de conception de fonctions de filtrage intégrées adaptées aux fréquences rf. Afin d'obtenir de bonnes performances à ces fréquences, une technologie mesfet GaAs digitale est choisie, ayant des transistors nmesfet depletes et enrichis de 25 GHz de fréquence de transition. L'approche proposée est basée sur le filtrage continu transconductance-capacité. Elle permet de résoudre des problèmes d'asservissement en fréquence, en mode commun, en phase et en gain dc. Ainsi, une nouvelle technique utilisant le principe des résistances négatives, est introduite pour résoudre le problème de la valeur élevée des conductances de sortie des transistors mesfet. Ceci permet d'améliorer le gain dc de la transconductance utilisée dans le système de filtrage. Différents filtres sont implémentés et mesures a des tensions d'alimentation de 1. 9 v: a) un filtre passe-bas du 1er ordre ayant une plage d'accord s'étendant de 500 mhz à 2. 2 GHz, et présentant une erreur de gain de l'ordre de 0. 25% ; b) un filtre passe-bande du 2nd ordre de 1. 1 GHz de fréquence centrale, présentant une plage d'accord de plus de 0. 5 GHz, et ayant un facteur de qualité réglable entre 0. 65 et 1. 3 ; c) un filtre passe-bas elliptique du troisième ordre d'une fréquence de coupure de 220 mhz. Une application du filtre passe-bande propose à un système de communication mobile permet d'en évaluer les performances pour des fréquences situées autour de 1 GHz. Un facteur de bruit de l'ordre de 5. 5 dB est prévu par les simulations.
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Visocchi, Pasqualino Michele. "Design of a fully tunable GaAs MESFET OTA - C integrator suitable for high-precision continuous-time filtering." Thesis, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265246.
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Zoccal, Leonardo Breseghello. "Desenvolvimento de dispositivos baseados em substrato de GaAs com passivação por plasma ECR." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260858.
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Orientador: Jose Alexandre DinizTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Este trabalho apresenta um método simples de passivação de superfícies semicondutoras III-V de substratos de arseneto de gálio (GaAs) e de heteroestruturas de fosfeto de gálio-índio sobre arseneto de gálio (InGaP/GaAs), que são utilizados em transist res de efeito de campo, MESFET (Metal-Semiconductor Field Effect Transistor) e MISFET Metal-Insulator-Semiconductor Field Effect Transistor), e transistores bipolares de heterojunção (HBT), respectivamente. O processo de passivação visa à máxima redução da densidade de estados de superfícies semicondutoras para níveis menores que 1012 cm-2. A alta densidade de estados na superfície do GaAs provoca corrente de fuga nas regiões ativas dos transistores MESFET e HBT, reduzindo o desempenho destes dispositivos. Além disso, impossibilita a formação de dispositivos MISFET sobre os substratos de GaAs, devido à alta densidade de estados na região da interface isolante-semicondutor. Para o estudo da passivação de superfícies, filmes de nitreto de silício (SiNX) são depositados diretam nte por plasma ECR-CVD (Electron Cyclotron Resonance - Chemical Vapor Deposition) sobre substratos de GaAs e heteroestruturas do tipo InGaP/GaAs. Os plasmas ECR foram analisados por espectroscopia de emissão óptica (OES), e identificou-se baixa formação de espécies H e NH na fase gasosa para pressão de processo de 2,5 mTorr. Os filmes de SiNX foram caracterizados estruturalmente por espectroscopia de absorção do infravermelho (FTIR) e por elipsometria, que indicaram, respectivamente, a formação de ligações Si-N e valores de índice de refração es de nitreto de silício. Capacitores MIS e transisto T foram fabricados para avaliar os efeitos da passivação sobre os dispositivos. Os excelentes resultados obtidos, tais como transist o e em torno de 2,0 nos filmres MISFET e HB ores HBT passivados apresentando maiores ganhos de corrente do que os não-passivados, e os transistores MISFET apresentando maiores valores de transcondutância do que os MESFET (que foram usados como dispositivos de controle), indicam que o nosso processo de passivação é muito eficiente, sendo completamente compatível com a tecnologia de fabricação de circuitos integrados monolíticos de microondas (MMIC)
Abstract: This work presents a simple passivation method for III-V semiconductor surfaces of gallium arsenide (GaAs) substrates and indium-gallium phosphide on gallium arsenide (InGaP/GaAs) heterostructures, which are us in field effect transistors MESFET (Metal-Semiconductor Field Effect Transistor) and MISFET (Metal-Insulator-Semiconductor Field Effect Transistor) and heterojunction bip lar transistors (HBT), respectively. The passivation process aims the maximum reduction of semiconductor surface state density at levels lower than 1012 states/cm2. The high surface state density on GaAs surface produces current leakage in active regions of MESFET and HBT transistors, reducing the device performance. Furthermore, the MISFET device formation on GaAs substrate is not allowed, passivation study, silicon nitride films (SiNX) are deposited by ECR-CVD (Electron Cyclotron Resonance - Chemical Deposition Vapor) plasma directly over GaAs substrate and InGaP/GaAs heterostructures. The ECR plasmas were analyzed by optical emission spectroscopy, (OES), and low formation of H and NH molecules in the gas phase was detected at process pressure of 2.5 mTorr. The SiNX film structural characterization was obtained by infra-red absorption spectrometry (FTIR) and ellipsometry, which, respectively, indicate the Si-N bo tive index values of about 2.0 at the silicon nitride films. MIS cap BT transistors were fabricated to verify the passivation process effect on devices. The excellent results obtained, such as higher and formation and refracacitors, MISFET and H current gain of passivated device compared to unpassivated HBTs and higher transconductances of MISFET devices compared to MESFET (which were used as control devices), indicate that our simple passivation process is very efficient, being fully compatible with monolithic microwave integrated circuits (MMIC)
Doutorado
Eletrônica, Microeletrônica e Optoeletrônica
Doutor em Engenharia Elétrica
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Tadyszak, Patrick. "Modélisation et caractérisation du bruit hyperfréquence dans des MESFETSs et HEMTs AlGaAs/GaAs sans grille à longueur de zone active ultracourte." Lille 1, 1997. http://www.theses.fr/1997LIL10152.
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Ce travail est une contribution a la modélisation et a la caractérisation du bruit hyperfréquence dans des structures sans grille de type mesfet et hemt algaas/gaas a longueur de zone active ultracourte. Dans le premier chapitre nous présentons les résultats concernant l'étude du bruit par la méthode de Monte-Carlo dans du silicium dégénère volumique de type n. Ce travail s'est avère être novateur dans le sens ou seules les grandeurs relatives au transport ont jusqu'a présent été étudiées en présence du principe d'exclusion de pauli. Le deuxième chapitre est consacre a la mise au point d'un banc de mesure de puissance disponible de bruit. Un effort particulier a été fourni afin d'optimiser la précision obtenue sur les mesures de bruit. Le troisième chapitre traite tout d'abord de la modélisation par la méthode de Monte-Carlo des caractéristiques statiques et de bruit hyperfréquence dans des structures ultracourtes il comporte des résultats expérimentaux confrontes a ceux du modèle théorique monte-carlo. Un modèle analytique unidimensionnel complémentaire nous a permis d'obtenir les variations au premier ordre des caractéristiques statique et de bruit du canal. Aucun effet relatif au caractère balistique du transport des électrons dans le canal n'a été détecte au niveau du bruit. Le quatrième chapitre porte sur une comparaison des caractéristiques électrique et bruyante de dispositifs sans grille de type mesfet et hemt. Une étude sur l'influence des transferts dans l'espace réel au niveau de la variance des fluctuations de courant ainsi que sur l'évolution des temsp de transit en fonction de la polarisation est ensuite développe. Enfin une analyse locale du bruit hyperfréquence est proposée.
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Utard, Christian. "Les Oscillateurs microondes faible bruit de fond à base de MESFET GaAs, TEGFET GaAIAs et transistor bipolaire modélisation, caractérisation et comparaison /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376190133.
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Garnier, Christophe. "Technologies de construction de transistors a effet de champ (mesfet et tegfet) sur gaas et algaas par auto-alignement de l'implantation." Université Louis Pasteur (Strasbourg) (1971-2008), 1991. http://www.theses.fr/1991STR13058.
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Le but de cette recherche est de mettre au point une technologie dite auto-alignee pour la fabrication de transistors integres a effet de champ (mesfet) sur un materiau specifique, l'arseniure de gallium, et sur l'une de ses heterostructures, l'algaas/gaas (tegfet). Le type de filiere technologique choisi est un procede a base d'auto-alignement de l'implantation des caissons n+ sous les contacts ohmiques (source et drain) par rapport a une grille supportant le recuit d'activation. Chaque etape critique du procede est analysee physiquement (sims) et electriquement (c(v) et effet hall). Cette technologie se deroule sur un substrat oriente a 45#o par rapport a la normale (axes (010) plutot que (011) pour eviter des effets piezoelectriques dissymetriques. L'implantation des caissons n+ et le recuit rapide (rta) s'effectuent a travers une fine couche (500 a) du metal de grille. La grille est composee d'or et de tiwsi pour supporter le recuit d'activation. Les implantations n+ sont espacees de la grille par une technique de double side-wall (dielectriques graves par gravure rie anisotrope). Les resultats de cette technologie sont suffisamment performants (rendement superieur a 90%, dispersion courte distance du vt inferieur a 10 mv, facteur de merite inferieur a 30 fj) pour envisager la construction de convertisseurs analogiques/numeriques de precision 6 bits sur gaas. La meme technologie appliquee a l'algaas/gaas donne aussi de tres bons resultats
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Chertouk, Mourad. "Transistors à effet de champ MESFET GaAs réalisés en désaccord de maille sur InP pour l'intégration micro-optoélectronique à 1,3-1,5 microns." Grenoble INPG, 1993. http://www.theses.fr/1993INPG0190.
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Après avoir brièvement indique, dans le premier chapitre, les différents matériaux et technologies aptes à une intégration micro-opto-électronique pour la réception a grande sensibilité ou l'émission a haut débit, nous présentons les motivations de l'hetero-epitaxie GaAas sur inp et les problèmes qui peuvent surgir lors de l'intégration de composants microélectroniques gaas sur désaccord de maille sur inp. Dans le deuxième chapitre, nous montrons la corrélation directe observée entre l'augmentation de l'épaisseur du buffer Ga As non dope et l'amélioration de la qualité cristalline et électrique du canal GaAs, ainsi que les performances statiques et dynamiques du MESFET. Dans le troisième chapitre, nous présentons différentes méthodes de caractérisation des pièges profonds, qui nous ont permis d'évaluer les paramètres du piège lie au désaccord de maille. Nous montrons aussi l'effet de ce piège sur le courant de fuite de grille. Une étude complète du bruit basse fréquence en l/f dans les MESFETS GaAs/InP est présentée dans le chapitre iv. Dans le dernier chapitre nous montrons l'effet du piège de désaccord de maille sur le facteur minimum de bruit hyperfréquence pour les mesfets GaAs/inp. Nous terminons par la réalisation et la caractérisation de modules de photo réception pin-MESFET GaAs/InP
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Utard, Christian. "Les oscillateurs microondes faible bruit de fond a base de mesfet gaas, tegfet gaalas et transistor bipolaire silicium : modelisation, caracterisation et comparaison." Toulouse 3, 1988. http://www.theses.fr/1988TOU30078.
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On presente une methode simplifiee de modelisation fort signal des mesfet et tegfet et transistors bipolaires. Ces trois types de transistors sont utilises dans un montage oscillateur dont les caracteristiques ont ete determines de trois facons differentes, analytique par simulation electrique temporelle et par mesures experimentales. On presente enfin une etude en bruit bf et bruit mf des transistors et des oscillateurs afin de determiner le composant le plus performant. Nous proposons trois facons de determiner le coefficient de conversion bruit bf - bruit mf, par des mesures directes; indirectes et par simulation temporelle
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Kamdem, Jean. "Étude et conception de processeurs de signaux rapides intégrés sur arséniure de gallium." Paris 11, 1988. http://www.theses.fr/1988PA112145.
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La première partie de ce mémoire est consacrée à l'étude du comportement des circuits intégrés logiques GaAs, aux températures cryogéniques. Notre approche a consisté à concevoir des portes logiques de base, adaptées à une structure de MESFET faiblement dopée, que nous avons mise au point compte tenu des modifications des propriétés du GaAs lorsqu'il est refroidi. Un modèle en commutation du MESFET GaAs dépendant de la température (de 77°K à 300°K), a été déduit de l'étude théorique de la structure. Des portes logiques optimisées pour 77. K, ont été conçues puis simulées et réalisées. La mobilité mesurée dans la couche active, varie de 5000 cm2 /V. S à 300°K, à 12000 cm2/V. S à 77°K, tandis que le temps de propagation par porte passe de 77 ps à 3ooK, à 38ps à 77K, pour un facteur de mérite de 1pJ. Les résultats obtenus ont démontré que le facteur de mérite ne dépend pas de la température. Le bon accord théorie-expérience obtenu sur les fonctions de transfert, la consommation par porte et les temps de propagation a permis de valider le modèle du transistor. La seconde partie a porté sur l'étude et la conception à 300°K, de multiplexeurs haut débit intégrés sur GaAs en logique BFL (Buffered FET Logic). On effectue d'abord une analyse théorique du comportement des principales structures BFL, lorsque les périodes d'horloges sont voisines des temps de propagation, et on en déduit les conditions qui limitent leur montée en fréquence. La notion d'impédance d'entrée et de sortie d'une porte logique en régime de haute vitesse est définie, et leur méthode de détermination est proposée. Cette étude est ensuite appliquée à la conception et à la réalisation de multiplexeurs à rang fixe ou programmable sur 2 à 4 entrées (342 à 472 composants par puce). Les débits numériques mesurés varient de 1. 5 à 2 Gbit/s, pour une consommation de 1W par puce. Pour terminer, on compare les performances de la logique cryogénique à celles de la logique destinée à la température ambiante.
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Parra, Thierry. "Modelisation du transistor mesfet gaas utilise en regime de forts signaux. Application a la conception d'un limiteur de puissance monolithique a distorsion de phase minimale." Toulouse 3, 1991. http://www.theses.fr/1991TOU30161.
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Nous presentons dans ce memoire l'analyse de la distorsion de phase qui apparait lors du fonctionnement fort signal du transistor a effet de champ sur arseniure de gallium (tec gaas), ainsi que la modelisation non lineaire mise en uvre dans le but de concevoir un limiteur de puissance monolithique a distorsion de phase minimale. Pour mener cette etude, nous avons effectue d'abord une caracterisation electrique approfondie d'un lot de tec (caracterisations continues, hyperfrequence petit signal et hyperfrequence fort signal). Ce travail nous a permis de degager les principales origines du phenomene et d'enoncer un critere de tri des composantes susceptibles, a l'interieur d'un lot, d'introduire une distorsion de phase minimale. Nous avons de plus elabore un modele phenomenologique non lineaire du mesfet permettant de rendre compte de la distorsion de phase au plan theorique, dans l'objectif d'obtenir des resultats de simulation suffisamment fiables et precis pour autoriser la conception de circuits integres micro-ondes monolithiques (mmic). L'utilisation de ces outils de simulation nous a conduit a proposer une topologie originale des circuits d'adaptation et de polarisation du composant permettant une minimisation de la distorsion de phase. Cette topologie a ete utilisee ensuite pour la conception d'un limiteur de puissance monolithique qui a ete par la suite realise et dont nous presentons les performances mesurees. Enfin nous avons valide notre etude pour d'autres applications du tec gaas, telles la conception d'un amplificateur a puissance variable (realise en technologie hybride) et la simulation d'un lineariseur par pre-distorsion
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El-Rabaie, E. S. M. "Microwave GaAs FET circuit design." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234136.
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Ahmed, Muhammad Mansoor. "Optimisation of submicron low-noise GaAs MESFETs." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242966.
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Amaeshi, Lawrence Lemchukwu Nnanyelugo. "Large signal characterization of microwave GaAs MESFETs." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/843717/.
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Large Signal modelling of GaAs MESFETs has often been based on the device material and electrical parameters. This approach, while helping in elucidating the physics of the device, does not help the device user very much. There is the problem of modelling and computation complexity, and of simulation time. Furthermore predictions based on such models may not be consistent with practical reality. A real-time large Rf signal characterization of the device, will help in the understanding of the device behaviour under Large Signal drive, and would also yield valuable results/information, useful to the device designer and user, especially in Large Signal applications. A large Rf signal characterization of GaAs MESFETs, employing Large Signal S-parameter (LSSP), and waveform distortion analysis techniques, is carried out. LSSP design is a natural extension of the SSSP approach where the LSSPs are known. And the LSSP design approach is simplified if the LSSPs are determined easily. Waveform distortions affect the device performance. A LSSP measurement system, (also applicable to SSSP measurements), including an uncomplicated, direct deembedding technique is developed. A direct technique of measuring the current and voltage waveforms of the microwave signals, at the device terminals, is also developed. Measurements of the LSSPs show that only the input parameters: S21 and S11 vary with the Rf. The results are explained against reported trends of variation. The non-linear elements are identified, and a subsequent Large Signal Model (LSM) of the DUTs developed and verified. It is demonstrated that LSMs cannot be generalised. However a systematic approach of determining the LSM of a given device is given. An improved model of the transconductance, Gm, in terms of the S-parameters, and a method to determine the LSSP from small signal parameters are developed and verified. The optimum incident Rf to determine the LSSPs at a given bias is given. The flow of forward conduction,IF is known to damage, by burn-out, the DUT. A limiting resistor was included in the gate external circuit to limit this effect, when large enough Rf was employed. The interaction of the IF with this circuit is investigated, and the self-limiting actions explained. The flow of Is. is found to degrade the output performance and device power added efficiency also. The waveform distortions are investigated, the main causes - the nonlinear elements, and the manner in which they affect the distortions are explored. The non-linearity in the Gm is shown to be the main cause of the output waveform distortion, especially before the onset of forward conduction by the gate Schottky diode. While the forward conduction If and the non-linearity in the depletion capacitance are responsible for the input waveform distortion, hence are secondary causes of output waveform distortions. In particular, the flow of If, due to large Vgs > 0, causes the saturation of the drain voltage, hence the output power. But the waveforms, were in particular insensitive to the output conductance. The results reaffirm the LSM developed. Finally future work is discussed.
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Ely, Kevin Jon. "Piezoelectric effects in GaAs MESFET's." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40029.
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Gallium arsenide MESFETS require protective passivation at several steps in their fabrication. A common film used for device passivation is silicon nitride. This passivation film is deposited on gallium arsenide substrates by chemical vapor deposition techniques and possesses high intrinsic stress. The stresses arise from the difference in the gallium arsenide and silicon nitride material properties, such as coefficient of expansion, density, modulus, and deposition temperature. The stress has been shown to cause electrical performance shifts in GaAs MESFET structures due to the piezoelectric nature of the gallium arsenide lattice.
This work develops a framework of mathematical models and experimental techniques by which the intrinsic stresses in the film and the GaAs substrate can be evaluated. Specifically, this work details the stress field and the electrical performance shifts in fully planarized self aligned gate GaAs MESFETS. The devices were 10 micron gate periphery FET devices with a 0.4 micron etched gate length. The test devices included both enhancement mode and depletion mode structures. The major contributors to the stress in GaAs devices was found to be the intrinsic stress effects of the silicon nitride passivation film. An externally applied stress, such as that applied to a package base that a typical GaAs device would be mounted into for actual service, was found to be insufficient to cause significant shifts in the device performance. The package body effectively reduces the transfer of stress to the device body and thereby minimizes the piezoelectric effect. The intrinsic stress effects are due to the deposition of the film itself. This intrinsic stress was found to have a significant effect on the device electrical characteristics. The stress was found to permanently shift the threshold voltage and current in 10 micron self aligned gate MESFETS. The shift was measured at 26 millivolts per 100 MPa film stress for depletion mode devices and 23 millivolts per 100 MPa for enhancement mode devices. For the maximum measured biaxial stress of -0.54 MPa in the gallium arsenide, the total measured shift was 140 millivolts. The level of shift is similar to that reported by earlier researchers. This piezoelectric shift has been modeled, with model predictions within 50/0 of the experimental values for the DFET devices and 11 % for the EFET devices.Ph. D.
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Barton, T. M. "Characterisation of the physical behaviour of GaAs MESFETs." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383294.
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Blight, S. R. "Surface and bulk traps in materials and devices for GaAs integrated circuits." Thesis, Cardiff University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383250.
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Dallas, Paul-Athos. "Determining the sources of flicker noise in GaAs MESFETs." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283338.
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Sodhi, Hemraj Singh. "Measuring and modeling low frequency dispersion in GaAs MESFETs." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38134.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 79).
by Hemraj Singh Sodhi.
M.Eng.
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Pierpoint, M. "Simulation and characterisation of GaAs MESFETs for power amplifier applications." Thesis, University of Leeds, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379759.
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Xue, Hongxi. "Modelling and analysis of GaAs dual gate MESFETS microwave mixers." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238153.
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Ahadian, Joseph F. (Joseph Farzin). "Phosphide-based optical emitters for monolithic integration with GaAs MESFETs." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/38054.
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Simpson, John C. R. "Characterization and modelling of GaAs MESFETs in the design of nonlinear circuits." Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/11390.
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The emergence of the MMIC as a cost effective, compact and enabling technology has increased the need for accurate CAD software. The performance of nonlinear MMICs must be evaluated during design using computer simulation, since they cannot be tuned after fabrication. Simulation relies upon accurate large-signal models for circuit components and this project involves the development of the GaAs MESFET large-signal model. In this work, the model is empirical and is derived entirely from characterizing S-parameter measurements over a range of bias levels and frequencies. Small-signal equivalent circuits are calculated from each set of S-parameter measurements and the nonlinear model is constructed from the complete set of equivalent circuits. Frequency dispersion in the conductances of the MESFET creates differences in the device characteristics at low and high frequencies. Extra nonlinear elements have been therefore added to the nonlinear model, to account for these effects. A series of MMIC circuits have been designed. Nonlinear measurements have been made and are compared with time domain simulations using the nonlinear model. Results indicate that this modelling approach is more accurate than one based on DC measurements, which does not account for the effects of frequency dispersion.
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Badan, Tomás Antônio Costa. "Projeto de uma tecnologia de fabricação de MESFETs para circuitos integrados em GaAs." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261416.
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Orientador: Furio DamianiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Este trabalho é uma contribuição ao desenvolvimento de transistores MESFETs em arseneto de gálio para uso em Circuito Integrados (CIs) de alta velocidade. Inicialmente são descritos processos de fabricação em arseneto de gálio: a obtenção de substratos monocristalinos, a implantação iônica, o recozimento para ativar os dopantes, a realização de contatos. É desenvolvido o modelo matemático que rege sua física do estado sólido, usado pelo programa PRISM. Os resultados obtidos com o programa de simulação de processos SUPREM-IV.GS foram fornecidos ao programa PRISM, que efetua uma análise do comportamento elétrico do MESFETs fabricados; esse procedimento foi realizado de forma iterativa, até serem obtidos parâmetros apropriados para a fabricação de transistores de enriquecimento e de depleção para CIs digitais
Abstract: This work is a contribution to the development of GaAs MESFETs transistors to use in high speed integrated circuits (CIs). Initially are described the GaAs manufacture processes: monocrystal substrate fabrication, ion implantation, thermal annealing to activate the implanted impurities, contact fabrications. It is developed the mathematical mo deI of the solid state physics used by the PRISM programo The results were first obtained with the SUPREM-IV.GS program that simulate the process and then passed to PRISM program that analyses the electrical behavior of MESFET devices; that procedure was done in an iterative way until the achievement of suitable parameters to the manufacture of both depletions and enhancement transistors to use in digital CIs
Mestrado
Mestre em Engenharia Elétrica
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Abdel-Motaleb, Ibrahim Mohamed. "GaAs MESFETS and their applications in digital logic and digital to Analog conversion." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/26637.
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The purpose of the work described in this thesis was to study the use of GaAs MESFETs in digital logic and digital to analog conversion. A part of this work was to test ideas by actually fabricating GaAs MESFET devices in our laboratory by implanting Si into LEC SI GaAs. Initially, the Rockwell "ion implanted planar process" was used. With this process high source and drain resistance result when the magnitude of the threshold voltage is reduced. A recessed gate process was then tried in order to reduce the series resistance, but it was difficult to control in order to achieve an acceptable uniformity. Sadler's self-aligned gate technique was then tried but an acceptable yield was found to be hard to achieve.
Based on the experience with the above methods, a Self Aligned Gate Technique Using Polyimide (SAGUPI) was developed. Using this technique it was found to be possible to reduce the series resistance of the transistor and achieve acceptable yields and uniformities.
The characteristics of devices fabricated using the ion implanted planar process were measured. The transistor I-V characteristic parameters, Schottky and ohmic contact parameters and implanted region parameters were measured at room temperature and as a function of temperature over the range from -80°C to 80°C. It was found that no large change in the speed of the circuit occurs over this range.
A new digital logic (the Common Drain FET Logic, CDFL) was developed for the application in Ultra High Speed Very Large Scale of Integration. The performance of the new logic was compared with that of other GaAs MESFET logic using computer simulation. The simulation results showed that the CDFL has potential for meeting the UHS VLSI requirements.
Two 3 bit Digital to Analog Converters (DAC) (one with MESFETS as current sources and the other with saturated resistors) were developed. MESFETs gave better current source characteristics than saturated resistors.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Chalapathi, K. M. "A study of the effects of radiation damage in GaAs MESFETs on device performance." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355937.
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Abdala, Mohammed Ahmed. "Characterisation of traps in GaAs MESFETs by low frequency noise, gM dispersion and oscillations methods." Thesis, Lancaster University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315539.
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Kandasamy, Sasikaran, and s3003480@student rmit edu au. "Investigation of SiC Based Field Effect Sensors with Gas Sensitive Metal Oxide Layers for Hydrogen and Hydrocarbon Gas Sensing at High Temperatures." RMIT University. Electrical and Computer Engineering, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080724.142015.
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This PhD thesis sets out to investigate novel Silicon Carbide (SiC) based field effect devices (Schottky and transistor structures), with gas sensitive layers for monitoring hydrogen and propene gases at high temperatures. The devices developed by the author were shown to exhibit sensitivities at least 1~2 orders of magnitude (voltage shift, ¢V) higher than those reported in literature. Not only did the author seek to investigate the gas sensing potential of such devices, but also he set out to study, analyse and establish the gas interaction mechanism of these novel sensors. High temperature tolerant hydrogen and hydrocarbon sensors are required in numerous applications such as: aerospace, nuclear power plant, space exploration and exhaust monitoring in automobiles. Monitoring these gases in a reliable and efficient manner is of great value in these applications, not only from a safety point of view but also for economical reasons. Hence there is an absolute necessity for simple, efficient and high performance sensors not only for monitoring and leak detection but also to function as part of a safety device to prevent accidents. The proposed sensor structure of combining SiC with gas sensitive oxide layers allow them to be operated at high temperatures, making them extremely appealing for direct or in-situ monitoring applications. The microstructural analysis performed using Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS) and Rutherford Backscattering Spectroscopy (RBS) provides no evidence of inter-diffusion between different layers, in spite of the sensors being annealing at 650 in O2, H2 and C3H6 atmospheres for approximately 50hrs. Samples in different conditions (as deposited, annealed and tested) were compared. The electrical properties of the MROSiC (current-voltage, I-V and capacitance-voltage, C-V characteristics) and MESFET (drain current-source drain voltage (ID-VSD) and transfer, (ãID-H2 concentration) characteristics) devices were measured in the presence and absence of H2 and C3H6. Several parameters such as barrier height, saturation currents, pinch-off voltages and channel conductance were determined from the electrical characteristics, and their influence on the device performance was studied. The authorfs proposed gas interaction model based on energy band diagram is well supported by the experimental data obtained.
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Weber, Michael Thomas. "Analysis of Zincblende-Phase GaN, Cubic-Phase SiC, and GaAs MESFETs Including a Full-Band Monte Carlo Simulator." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7500.
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The objective of this research has been the study of device properties for emerging wide-bandgap cubic-phase semiconductors. Though the wide-bandgap semiconductors have great potential as high-power microwave devices, many gaps remain in the knowledge about their properties. The simulations in this work are designed to give insight into the performance of microwave high-power devices constructed from the materials in question. The simulation are performed using a Monte Carlo simulator which was designed from the ground up to include accurate, numerical band structures derived from an empirical pseudo-potential model. Improvements that have been made to the simulator include the generalized device structure simulation, the fully numerical final state selector, and the inclusion of the overlap integrals in the final-state selection. The first comparison that is made among the materials is direct-current breakdown. The DC voltage at which breakdown occurs is a good indication of how much power a transistor can provide. It is found that GaAs has the smallest DC breakdown, with 3C-SiC and ZB-GaN being over 3 times higher. This follows what is expected and is discussed in detail in the work. The second comparison made is the radio-frequency breakdown of the transistors. When devices are used in high-frequency applications it is possible to operate them beyond DC breakdown levels. This phenomenon is caused by the reaction time of the carriers in the device. It is important to understand this effect if these materials are used in a high-frequency application, since this effect can cause a change in the ability of a material to produce high-power devices. MESFETs made from these materials are compared and the results are discussed in detail.
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Abdelslem, Ben Hamida. "Caractérisation électrique et optique de couches GaAs hétéroépitaxiees sur substrat InP et analyse des dispositifs MESFETs fabriques sur ces couches." Lyon, INSA, 1995. http://www.theses.fr/1995ISAL0026.
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Sa simplicité d'élaboration et ses performances élevées font du MESFET GaAs/lnP un composant tout à fait adapté à une utilisation dans les circuits optoélectroniques intégré monolithiques fabriqués sur substrat lnP. Ce travail a pour objectif essentiel l'étude des défauts électriquement actifs dans les couches GaAs hétéro-épitaxiées sur lnP et la compréhension de l'influence de ceux-ci sur les caractéristiques de fonctionnement des transistors MESFETs fabriqués sur ce matériau. L'interprétation du mécanisme qui induit une surcompensation des couches GaAs/lnP par rapport à celles de GaAs/GaAs a pu être mieux expliquée grâce à ne caractérisation complète par spectroscopie d'admittance (DLTS : Deep Level Transfert Spectroscopy), de photoluminescence, d'absorption dans l'infrarouge et de photoréflectance. Nous avons pu montrer que le caractère disloqué de ces hétérostructures induit une compensation partielle des porteurs non seulement par les centres profonds créés mais aussi par l'incorporation du silicium dans des sites cristallins complexés autres que donneurs. Grâce à une caractérisation électrique détaillée des caractenstiques du composant MESFET et des défauts électriquement actifs présents dans ce transistor nous avons été en mesure d’interpréter l'Influence des niveaux profonds de l' hetero-epitaxie sur ses performances. En particulier, une optimisation de l'épaisseur de la couche tampon et des traitements thermiques appliqués a pu être suivie et corrélée à l'action des défauts profondsOptoelectronic integrated circuits (OEICs) are presently developed for law cost and high performance devices in the 1. 3 μm - 1. 55 μm wavelength fiber communication systems. The very mature technology of gallium arsenide makes it highly attractive to combine GaAs electronic devices with lnP optical components on the same chip. The aim of this work is essentially the study of electrical defects influence on GaAs layers grown on lnP and their impact on MESFET devices performances. By using a complete variety of optical and electrical spectroscopy techniques (Photo -luminescence Photo-reflectance, lnfrared absorption and deep level transient sprectroscopy), we were able to give an explanation of the donor compensation mechanism observed on the GaAs/lnP layers if compared to the GaAs/GaAs layers. The compensation effect was shown to be partially due to complex defects involving silicon in acceptor sites. We also emphasized on the correlation between lattice – mismatch dislocations and electrical defects present in the GaAs layers. A detailed electrical characterization of MESFET devices showed the influence of the electrical active defects due to the lattice mismatch on the device performances. We also correlated the concentration of these defects to the buffer layer thickness optimization and to different heat treatments
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Kretly, Luiz Carlos 1950. "Dispositivos semicondutores de alta velocidade : contribuição ao modelamento e a implantação de tecnologia de MESFETs de GaAs com geometria micron e submicron." [s.n.], 1992. http://repositorio.unicamp.br/jspui/handle/REPOSIP/322512.
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Orientador: Attilio Jose GiarolaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Este trabalho descreve a tecnologia desenvolvida para construção de MESFETs de GaAs, (Metal Semiconductor Field Effect Transistors de Arseneto de Gálio), com geometria de porta mícron e submicron. Apresenta em detalhes todas as etapas para a construção destes dispositivos e os resultados obtidos. Mostramos que, a partir de fotolitografia convencional e procedimentos com técnicos de auto-alinhamento, é possível construir transitores MESFETs de GaAS para aplicação analógica (faixa de microondas) e com potencialidades para operação em circuitos intregrados digitais de GaAs. Transistores foram construídos usando esta técnica e as características estatísticas e dinâmicas obtidas estão de conformidade com as especificações típicas destes dispositivos, amplamente divulgados na literatura. Apresentamos, também, um amplo estudo, em forma de ¿tutorial¿, de várias alternativas tecnológicas para conturção de MESFESTs. Ainda, uma extensa análise dos modelos para MESFETs é apresentada, indicando a evolução destes, particularmente quanto à interpretação dos fenômenos ligados ao dispositivo. Uma simulação numérica é também desenvolvida para analisar o comportamento dinâmico de domínios estacionários de carga, em função da polarização de porta e de dreno para MESFETs de GaAs com porta submicron, o que permitiu identificar aprimoramentos a serem introduzidos nos modelos existentes
Abstract: this work describes the technology developed for the construction of GaAs MESFET¿s (Gallium Arsenide Metal Semiconductor Field Effect Transistors) with micron and submicron gate geometry. It describes in detail all the steps for the construction of these devices and the results obtained. It is shown that GaAs MESPETs, for analogical applacation in the microwave range and with potencial for operation in integrated digital circuits, may be constructed with conventional photolithography and with a self-aligment technique. Transitors were constructed using this technique and the DC and dynamic characteristics are in agreement with the specifications of typical MEFETs devices reported in the literature. A general study is also shown, in tutorial form, of the various technological alternatives for the construction of MESFETs. In addition, an extensive analysis of MESFETs models is also presented indicating their evolution, particulary with respect to the interpretation of of the phenomena associated with the divice. A numerical simulation was also developed for the analysis of the stationary charge domain behavior as a function of gate and drain bias of GaAs MEFETs with a submicron gate, thus allowing the identification of improvements to be introduced in the existing models
Doutorado
Doutor em Engenharia Elétrica